In order to take measurements or extract phase information, interferometry relies on the superposition (i.e., interference of waves) that are typically electromagnetic. Interferometry has important applications in a wide range of scientific and engineering pursuits from astronomy to quantum mechanics, and particle physics. Generally speaking, interferometry makes use of the superposition of waves in such a way as their combination has some meaningful property that can be measured by way of the interference pattern created, which is indicative of the phase difference between the two or more waves. Waves that are in-phase undergo constructive interference while waves that are out of phase will undergo destructive interference. Waves that are neither completely in-phase, nor completely out-of-phase will create an interference pattern, which can be used to determine the relative phase difference between the waves. These phase differences can become apparent in the macroscopic phase of quantum condensed matter systems, thereby making them of interest for applications as quantum interference devices.